Fix deadlock in J2K

#KT-17230 fixed

idea/src/org/jetbrains/kotlin/idea/actions/JavaToKotlinAction.kt

@@ -106,9 +106,7 @@ class JavaToKotlinAction : AnAction() {
 
 
             if (!ProgressManager.getInstance().runProcessWithProgressSynchronously(
-                    {
-                        runReadAction(::convert)
-                    },
+                    ::convert,
                     title,
                     true,
                     project)) return emptyList()

j2k/src/org/jetbrains/kotlin/j2k/JavaToKotlinConverter.kt

@@ -17,10 +17,12 @@
 package org.jetbrains.kotlin.j2k
 
 import com.intellij.lang.java.JavaLanguage
+import com.intellij.openapi.application.ApplicationManager
 import com.intellij.openapi.diagnostic.Logger
 import com.intellij.openapi.editor.RangeMarker
 import com.intellij.openapi.progress.*
 import com.intellij.openapi.project.Project
+import com.intellij.openapi.util.Computable
 import com.intellij.psi.*
 import com.intellij.psi.impl.source.DummyHolder
 import org.jetbrains.kotlin.idea.KotlinLanguage
@@ -64,15 +66,19 @@ class JavaToKotlinConverter(
 
     fun filesToKotlin(files: List<PsiJavaFile>, postProcessor: PostProcessor, progress: ProgressIndicator = EmptyProgressIndicator()): FilesResult {
         val withProgressProcessor = WithProgressProcessor(progress, files)
+        val (results, externalCodeProcessing) = ApplicationManager.getApplication().runReadAction(Computable {
+            elementsToKotlin(files, withProgressProcessor)
+        })
 
-        val (results, externalCodeProcessing) = elementsToKotlin(files, withProgressProcessor)
 
         val texts = withProgressProcessor.processItems(0.5, results.withIndex()) { pair ->
             val (i, result) = pair
             try {
-                val kotlinFile = KtPsiFactory(project).createAnalyzableFile("dummy.kt", result!!.text, files[i])
+                val kotlinFile = ApplicationManager.getApplication().runReadAction(Computable {
+                    KtPsiFactory(project).createAnalyzableFile("dummy.kt", result!!.text, files[i])
+                })
 
-                result.importsToAdd.forEach { postProcessor.insertImport(kotlinFile, it) }
+                result!!.importsToAdd.forEach { postProcessor.insertImport(kotlinFile, it) }
 
                 AfterConversionPass(project, postProcessor).run(kotlinFile, range = null)